Raboisson



Oct. 8, 1963" J. RABOISSON 3,105,993

TEXTILE DRAFTING MECHANISM Filed April 5, 1960 2 Sheets-Sheet 2 74; Fig? 74$ United States Patent 3,105,998 TEXTILE DRAFTING MECHANISM Joseph Raboisson, Soultz, France, assignor to Manufacture Alsacienne de Broches, Sonltz, France, a French company Filed Apr. 5, 1960, Ser. No. 20,136 Claims priority, application France Apr. 10, 1959 3 Claims. (Cl. 19244) The present invention has for its object improvements in textile drafting mechanisms for roving frames, spinning frames and like textile machines with a view to adjusting readily the length or distance of the drafting field.

As a matter of fact, the present requirements of the textile industry, lead always more to the working of a great variety of natural and synthetic natural fibres, whether considered singly or in admixture, the nature, length, size, fineness or elasticity and the like properties of which extend always over a larger range. These different varieties of fibres require normally different drafting field distances of the drafting mechanism or apparatus. This adjustment of the drafting field distances is ensured in the drafting mechanisms proposed hitherto by a modification in the distance between the rollers of the drafting mechanism which are mounted to this end in slidable members the position of which is adjustable. This arrangement leads to an intricate and expensive execution of the drafting mechanism and also to a tedious adjusting operation requiring a comparatively long time and this is all the more objectionable because the stock of fibres in process under predetermined similar conditions has often a comparatively small size so that it is necessary to frequently repeat the adjusting operation.

The present invention has for its object to remove the above mentioned drawback and to this purpose, the drafting mechanism according to the invention includes at least four pairs of bottom and top rollers mounted preferably in stationary locations and of which at least the top rollers may be exchanged for each other, the bosses of at least the top rollers being designed in at least two different manners, one of the four pairs of rollers being associated with the conventional top and bottom aprons.

According to another feature of the invention, the outer surface of the bosses of a number of top rollers are unbroken, while the other top rollers have outer boss surfaces which are recessed in their medial area.

According to another feature of the invention, the top rollers which have a recessed medial area may be obtained either through moulding or through cutting from the bar said area within the mass of the original cylindrical boss or again by fitting a rubber or the like suitably shaped covering over an unbroken cylindrical member and lastly by a fitting of two strip-shaped coverings over the ends of a cylindrical member or through any other suitable means.

According to still another feature of the invention, the aprons occupy a stationary position, preferably over the rollers of the third pair of rollers in the direction of progression of the sliver or roving at least the top apron being adapted to cooperate either with a roller having an unbroken outer boss surface or else with a roller provided with a surface the medial area of which is recessed.

Other features and advantages of the invention will appear from the reading of the following disclosure, reference being made to the accompanying drawings, wherein:

FIG. 1 is a diagrammatic sectional view showing, in the transverse plane of symmetry of one of the twin rollers forming part of the top rollers, a first arrangement of a drafting mechanism according to the invention,

adapted to provide for the drafting of longer staple lengths of fibres.

FIG. 2 is a sectional view of the drafting mechanism of FIG. 1 arranged for the drafting of shorter fibres.

FIG. 3 is a sectional view of the drafting mechanism of FIG. 1 arranged for the drafting of still shorter fibres.

FIG. 4 is a diagrammatic axial cross-section of a top roller constituted by half or twin rollers having an unbroken boss outer surface.

FIG. 5 is an axial sectional view of an embodiment of the half or twin rollers forming a top roller and the boss outer surface of each of which is recessed in its medial area.

FIG. 6 is an axial sectional view illustrating another embodiment of twin rollers provided with a medially recessed boss outer surface.

FIG. 7 is still another modification of a roller having a medially recessed boss outer surface.

FIG. 8 is an elevation view illustrating the cooperation of aprons with top rollers, having a recessed boss outer surface.

FIG. 9 is a longitudinal sectional view of a modification of the bottom roller.

1n the embodiment illustrated in FIG. 1, the drafting mechanism according to the invention includes four pairs of associated top and bottom rollers.

The bottom rollers 1, 2, 3 and 4 may have fluted bosses a and b as illustrated in FIG. 8, or less, bosses with corrugations or spikes. They may also have coverings c and d of yelding material which has a suitable coefficient of friction as illustrated in FIG. 9.

The bottom rollers 2, 3, 4, revolve at the same speed or substantially so, with a view to very slightly tensioning the fibre sliver or roving between them, while the bot-tom front roller 1 revolves at the speed required for producing the desired drafting.

The bottom rollers cooperate with the top rollers 5, 6, 7 and ,8. According to :a feature of the invention, the different rollers are positioned at predetermined unvarying locations, but the top rollers 5, 6, 7 and 8 may be interchanged.

Furthermore, according to another feature of the invention, the outer surfaces of the bosses of the top rollers are designed in two different manners. In the case illustrated, the rollers 5 and 6 are provided with a boss of an unbroken surface, which is obtained for instance as illustrated in FIG. 4 by means of a cover 9 of rubber, cork or the like, fitted over the twin rollers 5a and '5!) respectively.

The bosses 5a and 5b of the rollers 6* may be adapted to rotate independently of each other or dependently and the rotation in unison of the two bosses is necessary in the case of the spinning of roving fed from the so-called double-roving spools. The roller 5 is always provided with independently rotating bosses.

The rollers 7 and 8 in contradistinction include a medial area which is recessed and in fact three different embodiments are possible for the roller 8 as shown in FIGURES 5 to 7.

In FIG. 5, the twin rollers 8a and 8b are cut from the bar so as to produce recesses 10a and 16b which are bounded at their ends by the collars 11a, 12a and 11b, 121) respectively. It is furthermore preferable for the bosses of said rollers 7 and 8 to be executed so as to be capable of rotating independently of each other.

'In the embodiment illustrated in FIG. 6, the twin rollers 8a and 8b are each provided with a cover 13a and 13b respectively of a rubber, metal or the like suitable material which is shaped so as to be provided with a corresponding recess ll ta or 14b bounded by terminal collars.

a medial recessed area as shown at 17a and 17b respectively.

In the arrangement according to FIG. 1, the top rollers and 6 which have unbroken surfaces, cooperate with the bottom rollers 1 and 4 while the top rollers 7 and 8 the outer surfaces of which are recessed, cooperate with the bottom rollers 3 and 2; furthermore the pair of rollers 2-8 cooperates with the conventional top and bottom aprons 18 and 19.

This arrangement is intended for the drafting of very long staple fibres; as a matter of fact the drafting of the rovings or slivers 2i) progressing in the direction of the arrow 21 is obtained between the back roller nip 4-6 and the front roller nip 15, over a maximum distance designated by 22, while the rollers 7 and 8 having a broken or recessed surface exert a mere guiding action without any nipping of fibres. As apparent from inspection of FIG. 8, the top apron 19 engages while in contact with the sliver 20 the recess ldb in the top roller 8 which is assumed to be similar to the roller illustrated in FIG. 5. Thus, the aprons 18 and 19 exert a mere slight holding action on the fibres without preventing their sliding with reference to one another. It should also be remarked that the bottom twin rollers a and b may be replaced by rollers carrying small projections or spikes so as to improve the drive of the aprons.

In the arrangement according to FIG. 2, the interchangeable t-op rollers are positioned in a manner such that the rollers 5 and 6 having unbroken surfaces cooperate with the corresponding bottom rollers 1 and 3 respectively while the further rollers 7 and 8 provided with recessed surfaces cooperate with the bottom roller 4 and with the bottom roller 2 and with the top apron 19 respectively. In this case, the drafting field extends between the bottom rollers 1 and 3 as shown by the reference 23.

The arrangement according to FIG. 3 corresponds to the drafting of still shorter staple fibres. As a matter of fact, the rollers 5 and 6 with unbroken surfaces cooperate with the bottom rollers 1 and 2 so as to limit the drafting field to the distance between the rollers 1 and 2, as shown at 24. It should be remarked that the aprons i8 and whip between them in this case the sliver 20 so as to ensure the drafting of the latter, since the top apron 19 cooperates with the roller 6' provided with an unbroken surface, while the rollers 7 and 8 having a recessed outer surface, serve only for guiding purposes.

As apparent from the preceding disclosure, the length of the drafting field is adjusted simply by changing the location of the top rollers 6, 7 and 8, which forms a speedy operation. Furthermore, the cost price of such a drafting mechanism is substantially lower than that of any of the known drafting mechanisms since it requires no longer the numerous parts incorporated with the conventional drafting mechanisms and adapted to adjust the length of the drafting field inside the member carrying the bottom rollers or inside the arms carrying the top rollers. In the improved drafting mechanism described, the bottom rollers may be merely carried by stationary holders engaging the spindles of said bottom rollers while the arms carrying the top rollers may be merely provided with four stationary spindles over which are clamped the spring-weighted saddles carrying the top rollers.

Of course, the embodiments described hereinabove and illustrated in the drawings are illustrated solely by way of mere examples and by no means in a limited sense and it is possible to modify in any suitable manner the shape, nature, arrangement and fitting of their components, without widening undulythereby the scope of the invention, as defined in the accompanying claims. Thus it is possible to adjust within a predetermined range the longitudinal position of the rollers in order to increase the fineness of adjustment obtained by interchanging the position of two rollers. The number of pairs of rollers may be also larger than four. .011 the other hand, the top interchangeable rollers may be replaced not only by one of them, but also by any other roller having particular features corresponding to the work to be executed.

The use of the drafting mechanism disclosed is not limited to the spinning frames and it may serve with the same advantages and the same excellent results for drawing frames, slubbers, roving frames, and the like.

I claim:

1. In a drafting apparatus, in combination, at least four consecutive spaced pairs of driven drafting rolls disposed spaced from each other at fixed predetermined intervals defining a drafting field having a variable length suitably adjustable for the length of the fibers being drafted, each pair of rolls comprising an elongated lower roll and an upper roll, the upper rolls of at least two of next successive pairs of said pairs of rolls being interchangeable for varying the length of said drafting field, one of the upper rolls of said pairs for varying the length of said drafting field comprising a tension applying roll having two axially spaced smooth peripheral portions cooperative with the corresponding lower roll, the other of said upper rolls for varying the length of said drafting field having two axially spaced portions with a neck of reduced diameter between them, each of said two portions comprising two axially spaced collars defining axially on the corresponding portion a section of predetermined reduced diameter, the sections of said two portions having a common diameter, and said one of the interchangeable upper rolls for varying the length of the field being disposed alternatively in position in one of the said pairs of rolls for varying the length of said field.

2. In a drafting apparatus, in combination, at least four consecutive spaced pairs of driven drafting rolls disposed spaced from each other at fixed predetermined intervals defining a drafting field having a variable length suitably adjustable for the length of the fibers being drafted, each pair of rolls comprising an elongated lower roll and an upper roll, the upper rolls of three of next successive pairs of said pairs of rolls being interchangeable for varying the length of said drafting field, one of the upper rolls of said pairs for varying the length of said drafting field comprising a tension applying roll having two axially spaced smooth peripheral portions cooperative with the corresponding lower roll, the others of said upper rolls for varying the length of said drafting field having two axially spaced portions with a neck of reduced diameter between them, each of said two portions comprising two axially spaced collars defining axially on the corresponding portion a section of predetermined reduced diameter, the sections of said two portions having a common diameter, and said one of the interchangeable upper rolls for varying the length of the field being disposed alternatively in position in one of said three next successive pairs thereby to determine the length of said drafting field.

3. In a drafting apparatus, in combination, at least four consecutive spaced pairs of driven drafting rolls disposed spaced from each other at fixed predetermined intervals defining a drafting field having a variable length suitably adjustable for the length of the fibers being drafted, each pair of rolls comprising an elongated lower roll and an upper roll, a driven upper endless apron and a driven lower endless apron cooperative with a corresponding pair of said rolls, the upper rolls of three of next successive pairs of said pairs of rolls being interchangeable for varying the length of said drafting field, one of the upper rolls of said pairs for varying the length of said drafting field comprising a tension applying roll having two axially spaced smooth peripheral F portions cooperative with the corresponding lower roll, the others of said upper rolls for varying the length of said drafting field having two axially spaced portions with a neck of reduced diameter between them, each of said two portions comprising two axially spaced collars defining axially on the corresponding portion a section of predetermined reduced diameter, the section of said two portions having a common diameter 'and said one of the interchangeable upper rolls for varying the length of the field being dis posed alternatively in position to cooperate with said upper apron and in one of the pairs of rolls upstream thereof in dependence upon the direction of travel of the fibers through said apparatus.

References Cited in the file of this patent UNITED STATES PATENTS Zalkind Aug. 26, 1947 Shaw Mar. 11, 1952 Spencer Oct. 21, 1958 Noguera. Apr. 5, 1960 

3. IN A DRAFTING APPARATUS, IN COMBINATION, AT LEAST FOUR CONSECUTIVE SPACED PAIRS OF DRIVEN DRAFTING ROLLS DISPOSED SPACED FROM EACH OTHER AT FIXED PREDETERMINED INTERVALS DEFINING A DRAFTING FIELD HAVING A VARIABLE LENGTH SUITABLY ADJUSTABLE FOR THE LENGTH OF THE FIBERS BEING DRAFTED, EACH PAIR OF ROLLS COMPRISING AN ELONGATED LOWER ROLL AND AN UPPER ROLL, A DRIVEN UPPER ENDLESS APRON AND A DRIVEN LOWER ENDLESS APRON COOPERATIVE WITH A CORRESPONDING PAIR OF SAID ROLLS, THE UPPER ROLLS OF THREE OF NEXT SUCCESSIVE PAIRS OF SAID PAIRS OF ROLLS BEING INTERCHANGEABLE FOR VARYING THE LENGTH OF SAID DRAFTING FIELD, ONE OF THE UPPER ROLLS OF SAID PAIRS FOR VARYING THE LENGTH OF SAID DRAFTING FIELD COMPRISING A TENSION APPLYING ROLL HAVING TWO AXIALLY SPACED SMOOTH PERIPHERAL PORTIONS COOPERATIVE WITH THE CORRESPONDING LOWER ROLL, THE OTHERS OF SAID UPPER ROLLS FOR VARYING THE LENGTH OF SAID DRAFTING FIELD HAVING TWO AXIALLY SPACED PORTIONS WITH A NECK OF REDUCED DIAMETER BETWEEN THEM, EACH OF SAID TWO PORTIONS COMPRISING TWO AXIALLY SPACED COLARS DEFINING AXIALLY ON THE CORRESPONDING PORTION A SECTION OF PREDETERMINED REDUCED DIAMETER, THE SECTION OF SAID TWO PORTIONS HAVING A COMMON DIAMETER AND SAID ONE OF THE INTERCHARGEABLE UPPER ROLLS FOR VARYING THE LENGTH OF THE FIELD BEING DISPOSED ALTERNATIVELY IN POSITION TO COOPERATE WITH SAID UPPER APRON AND IN ONE OF THE PAIRS OF ROLLS UPSTREAM THEREOF IN DEPENDENCE UPON THE DIRECTION OF TRAVEL OF THE FIBERS THROUGH SAID APPARATUS. 